Cards differ in their rarity, represented by the number of stars they have.

Silver cards are regular cards: they have a silver frame and can have from 1 to 5 stars.

Gold cards are rare cards: you can recognize them by their golden frame. Such cards can only have 5 stars.

A card type and its star value matter when exchanging cards and accumulating Duplicates:

- Gold cards can't be sent to other players.
- A silver card can only be exchanged with other players if it's a duplicate.

As you accumulate duplicates, their stars add up. Once you've collected enough stars from duplicate cards, you can open reward chests to get even more rewards. Duplicates of gold cards give you 10 stars for unlocking chests.